P24B6: Particulate Matter Sensor Heater Control Circuit High
What to do
Ask for the connector to be checked first — including that it is plugged in and that its terminals are not scorched. This circuit carries current, so a failing connection here burns rather than just corroding, and the damage is usually visible.
If other faults from the same sensor are stored, expect them to be caused by this one. The heater is how the sensor cleans itself, so one repair normally clears both.
Mention any recent work under the car. A sensor left disconnected after exhaust or filter work produces this code exactly, and that is worth eliminating before a part is ordered.
What this code means
The heater control circuit for the particulate matter sensor is sitting higher than commanded.
As with every high-side control code, this means either a short to a supply voltage or an open circuit, and the module cannot tell which from the inside. The measurement that separates them is made at the connector with the sensor unplugged, and it takes minutes.
On a heater circuit specifically, an open is the more likely of the two. The element carries current and heats; elements fail open far more often than they fail short, and a burnt terminal in the connector produces the same reading for the same reason.
So inspect the connector for heat damage rather than just continuity. A terminal that has been running warm discolours the plastic around it, and that discolouration is the visible history of a connection that has been getting worse for a long time.
The consequence is the same as the low-side version and worth repeating: without its heater, this sensor cannot clean itself, so it measures once and then reports nothing meaningful. Expect a sensor performance code alongside, and expect it to clear when the heater is fixed.
A sensor left unplugged after exhaust work reads exactly like an open heater circuit, so confirm it is connected before anything else.
Likely causes
Start here
- Open circuit in control wiring · moderate
- Faulty particulate matter sensor · moderate
- Corroded or loose connector · easy
Less common
- Sensor left disconnected after previous work · easy
- Wiring shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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